We review the Club3D Radeon HD 6870 X2. A dual-GPU Barts based graphics card. AMD had nothing to do with this design this is a custom design product. Admittedly we just love that stuff. So we'll head...

Since they relies on AMD for Crossfire support in drivers. I don't think so (for quad-fire). And the review did talked about adding a "3rd". So that concludes that "number one and two" are on this single card.
Sweet product, too bad of the slightly higher prices. If it was (slightly) lesser than 2 HD6870 it would be a killer product.

I want to see a video comparison in Crysis 2, ultra settings, full DX11 full textures "on" between the GTX 590 and this comparatively inexpensive multi-gpu Option. The real test will be in Quad-fire mode for both which Crysis 2 supports, if it looks stellar (which it should) I think I will buy 2 of these instead of two gtx 590's.

That even the mighty gtx 580 can drop to 1.8 fps in crysis 2, not surprising, crysis 2 at ultra is a beast to run without frame dragging, smearing, frame dropping, and jumpiness seen in MANY video cards. So on the low end you got the 1 FPS in crysis 2 seen during the review, but that's not far from the 1.8 seen on the above benchmark. Haha! if you look closely that's a benchmark for 2 GTX 580's in Sli!! I see that 2 580's do have a higher top end FPS, but the low end matches the review results of the 6780x2. I'd say there's not much difference there except in price.

Someone should make a list of gpu's that can't handle Crysis 2 so we'll all know what not to buy. (futureproofing)

According to online posts I have been reading from overclocking, hardware fanatics, two of these 6870x2's ($1040) will beat a 6990 ($780-$1200) hands down in quadfire not to mention what they could do with proper watercooling and tweaking.

If the price for each 6870x2 were $375 they would kill the price per performance point of the gtx 590 by blowing it out of the water.